Track geometry error

[Graeme1]

I called customer service today re easterner se issues. They advised for track issues if you didn’t want to pin it laying weight on track over night should solve the issue which should also eliminate the coach scraping on curves too

[Rallymatt]

There is an easy fix!

I have seen someone comment that of some track manipulation improves things so tonight I did some experimenting.

Gently hold the ends of a curve and ‘open’ it out, some will click some won’t.

Once this stress in the curve has been relieved the track piece lays flat and 12 make a perfect circle with no overlap.

For my track it was just a fluke that the error aligns with a 1 sleeper ‘out’

crisis over 😁

[ntpntpntp]

Yup, I flexed my curves to de-stress them as mentioned in a previous post.

[Fredoxford-344906]

To quantify the curved track error, if you look at the anticlockwise end of one piece of track, the inside rail is approximately 0.5mm shorter than it should be relative to the outside rail. This angle error is quite large.

[Fredoxford-344906]

There is a bit of variation, when the anticlockwise inside rail is short the other end of the track is the opposite ie inside rail approximately 0.25mm long.

This makes sense as all 4 rails are probably cut in one setup. The tooling possibly needs adjustment so the track position it tweaked a bit.

[LTSR_NSE]

@Fredoxford - the rails are not glued/fixed to the sleepers, they are simply gripped by the moulded “chairs”. Therefore if a rail is ‘too short’ at one end and ‘too long’ at the other, it just needs to be gently coaxed/slid into the correct place.

Other responses above have already confirmed that this gentle correction solves both of the apparent ‘flaws’ (circle overlap & warped/cambered sleepers). Therefore no tooling needs correcting - it is most likely just inaccurate assembly (or possibly massive temperature fluctuations during transportation).

I am not suggesting that customers should have to correct brand new items - but anyone who has held flexible track has the advantage of immediately recognising the ‘flaws’ as something that is (fairly) easily corrected.

[ColinB]

I have just watched the Chadwick Model railway video and I must admit I have never made a full circle to check that the geometry is correct, I wonder if he had some prior knowledge that there was an issue. It is something Hornby should be doing, it should be part of the sign off procedure. Unfortunately Hornby haven't learn that if you bring out something new to a range of prospective new customers it mustn't have fundamental errors, the error in the page numbering in the manual is unforgiveable. It immediately wipes out all the other good work you have done with the rest of the product. It appears the sloppyness and lack of quality awareness that has grown in their OO models has moved to their new venture.

[Fredoxford-344906]

Overall I think the inside rail is too short, that's the problem.

[Fishmanoz]

I have just taken delivery of my Easterner set so got out the R3 curves to investigate.

First I put them together straight out of the box with the results similar to previously reported:

• There is a significant reverse camber
• When the curves are joined with minimal gaps and without kinks, there is a 7 sleeper overlap
• the diameter measured 690mm-695mm at various points around the circle versus the nominal 706mm

So I then disconnected each curve and applied gentle outward pressure. On every rail section, the rails could be felt moving in their chairs, usually 2-3 times. Others have described the movement as producing a crack but I would say not that extreme.

Following this I reconnected and found:

• slight reverse camber still but nothing to cause a problem in train running or in gluing track to a baseboard
• no sleeper overlap and the full circle joined up without kinks or rail gaps at the joins
• the diameter measured 705mm-710mm, near enough to the nominal 706mm once perfectly aligned.

My conclusion:

• the design and construction of the individual parts, inner and outer rails and the sleepers, are all correct
• the assembly tooling needs slight adjustment to avoid pre-stressing of the curves to a slightly lesser radius than the correct 353mm Radius 3.

Clearly the track should have come unstressed and Hornby should address this with the factory. However, I believe even first time modellers will have little problem doing the necessary de-stressing as only very gentle pressure is needed to correct the problem and the track tells you by feel when you’ve achieved it.

PS. Posters have recently raised 2 extra threads on this exact same topic with slightly different titles. I’ve referred everyone back to this thread and suggested the others be locked. Not being critical, this thread had descended to page 2 in the TT:120 forum so not surprising it was missed.

[Hobby11]

Thanks, Fishmanoz, a fair review of the issues. Mine actually lined up as well but need some gentle massaging to sit flat! BTW I think the quoted radius is centre to centre of the track, is that what you measured?

I'd agree with the comment regarding duplicate threads, it's getting much worse. What doesn't help is that there are no sub sections within the TT part of the forum, at least that way people might see similar threads before starting one of their own. I don't know who the Mods are but hopefully one may see this post!

[Fishmanoz]

Yes Hobby, my measurements were centre to centre, or inner rail one side to outer rail the other, same thing.

[96RAF]

Moderators are identified by a label under their user name to left of each post. That said Moderators cannot generate sub-sections of forums indeed none of the other sections have sub sections. To introduce a sub section would require IT to task developer resource and that ain’t going to happen.

The simple answer is if you want a sub section entitle your post such that folk will repost to thread and generate duplicate threads. This will also help future searches for the same info.

[Bexhill Donkey]

Sam's Trains has reported an apparent error with the track geometry, first noticed by Charlie at Chadwick Model Railway.

But don't worry folks!

The track geometry is correct.

It looks as though a circle requires either 23 TT8016 half curve 3rd radius, or 11 TT8005 Curve 3rd radius and 1 TT8016. It is just that a piece of TT8016 has not been supplied with the set. You get 12 3rd radius track pieces in the set, but you need 11, plus one half-length 3rd radius curve to make a circle, as the picture below shows.

[Silver Fox 17]

It is that a circle requires either 19 TT8016 half curve 3rd radius, or 9 TT8005 Curve 3rd radius and 1 TT8016. It is just that a piece of TT8016 has not been supplied with the set. You get 10 3rd radius track pieces in the set, but you need 9, plus one half-length 3rd radius curve to make a circle.

 

 

Sorry but totally rubbish Bexhill. I have posted how the 12, (not 10 as you state) curves should be manipulated to give you a proper flat circle.

 

 

I have no idea of your logic to make a circle with 9 curves of 30 degrees and 1 curve of 15 degrees when cut makes a circle.

Please check your maths as 12 x 30 degrees = 360 degrees ( a full circle).

By your suggestion 9 x 30 + 15 = 285 degrees.

 

 

[Somerset Modeller1707823104]

Silver Fox, you just beat me to it. as you say, the clue is in the description; all 30 degree curves ( 1st., 2nd., 3rd. & 4th. radius) employ 12 to form a circle.

[ntpntpntp]

I'll assume @bexhill donkey was being a bit tongue-in-cheek there grinning

Even straight out of the box my set of R3 ended up only about 10-15mm overlapped, and the reverse flex trick on each piece cured it easily.

[Fishmanoz]

Mine was more than 10-15mm at 7 sleepers overlap but easily fixed as I posted in a lot of detail in my post on the previous page.

[Rallymatt]

Worth noting I had to manipulate every single curve on my layout using Peco track….. well it’s flexi track 🤣

[Silver Fox 17]

As I have written the base and rails are okay when they have been manipulated by hand.

They are not one sleeper too many, they are correct and when done give the correct diameter.

I wote to Simon Kohler and sent photos of my findings and he said they are looking into seeing if the track can be "destressed" during manufacture.

[Rallymatt]

Mr Fox, I fully agree, it was just a bizarre quirk mine equated to 1 sleeper out. Manipulation of the sections showed some were actually perfect and some just needed to relax and the end result was a spot on series of pieces.

PS The last Hornby OO loco I bought was Silver Fox in its silver grey livery. It was pride of place on my mantle piece for 10 years, no space to build an OO layout… then years later TT:120, back in the game